“Every time I think I’m gonna be photographed, I wonder if somebody will see what I’m wearing, and if it’ll help ’em put somethin’ together, maybe for school?” she reveals.

That drive to inspire is what pushes the star to create, both in the workroom and in her own life. “I always wonder if what I’m wearing will be something that people would compliment, or want to wear,” she continues. “I don’t ever get ready just for myself, ever.”

So the singer-turned-designer hopes to bring her motivational mentality to her new mentor role on Fashion Star, which premieres Tuesday on NBC. (Nicole Richie and designer John Varvatos costar.) “I’d hate to be a judge … I don’t want to crush [the contestants’] dreams,” she says. “I’d rather help ’em reach the best of their ability that week.” Spoken like a true mentor! For more with Simpson, pick up the April issue of ELLE, on newsstands now.